Sealing means for centrifugal pump impellers



Patented June 13, 1939 SEALING MEANS Fon CENTRIFUGAL PUMP nur ELLERs v Robert Gilmore Le Tourneau, Peoria, Ill., assign# or to R. G. Le Tourneau, Inc., Peoria, Ill.

Application June 21, 1937, Serial No. 1,452,299

2 Claims.

This invention relates to centrifugal pumps and particularly to a means for preventing leakage betweenthe suction` end of the impeller and the pump casing.

5 The principal object of my invention is to provide a sealingmeans for the purpose arranged so that the different pressures on the suction and discharge side of the impeller will both aid in maintaining the desired leak-proof seal, and in Y m which -oil is used in addition to aid in the sealing action, while being prevented from escaping in any measurable quantities Ainto the pump chamber.

' A further object of the invention is to produce a smiple. and inexpensive device and yet one vwhich will b e exceedingly effective for the purpose for which it is designed.

These objects I accomplish by'means of such structure and relative arrangement of parts as o will fully appear by a perusal of the following specification and claims.

In the drawing similar characters ofreference indicate corresponding parts in the several views:

Figure is a fragmentary sectional Aelevation of a centr1fugal pump equipped with my improved seahng means. i

Figure 2 is a fragmentary enlarged section of the impeller at its suction end, and the cooperat mg sealing devices.

Referring now more particularly to the characters of reference on the drawing, the pump' casing I is preferably fabricated from a number of s plates welded together to provide great strength and rigidity, and includes parallel front and back walls 2 and 3 respectively.

Projecting from the front wall 2 is the intakey conduit 4. Alined with said intake conduit and projecting a short distance into'the casing from 40. and secured on said wall is a short sleeve 5. This is preferably made of an alloy containing chromium, cobalt and tungsten, which provides an extremely hard metal and is rust proof.

The impeller 6 of the standard shrouded type is disposed in the casing concentric with the sleeve 5 and has a central intake opening 1 as usual somewhat larger than the external diameter of the sleeve. 0n its opposite side the impeller is secured on a drive shaft 8 which is made o relatively large to eliminate vibration and whichis mounted on roller bearings lor the like dis-5 posedin an extension I a of the casing I.

Between the forward bearing 5 and the interior of the casing, a collar I0 is secured on the I u shaft which is engaged by oppositely disposed communication with a source-of oil such as sealing cup leathers II seated in a chamber I2 formed in the end of the'casing about the collar and which, 'between adjacent cup leathers, is in o ilcupIS. p The nost annoying and usual source o f pressure leakage however is between the suction end of the impeller and the adjacent end of the casing; and my improved sealing means 'to prevent leakage at this point will now be described. 'I'he lo impeller at-its intake vend is formed with an outwardly projecting flange I4 fixed on its periphery with a band I5 of the same alloy as is`usedfor the sleeve 5. 'I'his flange is spaced from the casing wall 2 somewhat andsurrounds the inwardly 15 projecting portion of the sleeve 5, being disposed in spaced relation to and'betwe'en said sleeve and an outer ring I6 concentric therewith and, se-

" cured on the inner face of the wall 2.

The band I5 is, engaged by one face of a caged 2o cup leather I'I. This'is of right angle form in f cross section and is disposed with its opposite face parallel to and adjacent the wall 2. In this manner,`the angle included between the sides of the leather is open to the high pressure area of the 5 casing outwardly of the impeller, so that such pressure forces the two sides of the leather into firm sealing contact with the band I5 and the wall 2, and holds the leather against rotation with the impeller. A sealing gland is thus provided which is maintained in sealing relation by the pressure in the pump casing, and which allows of any slight axial movement of the impeller without destroying the seal.

The flange I4` of theimpeller about the opening 1 is circumferentially recessed as at I8 so as to form a flat shoulder adjacent the plane of the inner end of the sleeve 5, for engagement with one side of another caged right angle cup leather I9. The other side of this leather rides on the band 5, sc that another sealing gland, inwardly disposed relative to the gland- II,'is thus'provided.' The angle included between the sides of the leather I9 thus faces 'toward the wall 2, or away Vfrom the interior of the impeller. The suction within the impeller in the intake opening can thus act to draw the leather against the shoulder I8 of the impeller, making a firm seal at this .point and holding lthe leather so that it rotates with the impeller while maintaining a propersealing joint with the sleeve 5.

Additional means to prevent leakage past the glands is provided by means of oil, maintained in an enclosed Ichamber 20 formed between the ange Il, the wall 2 and the glands, from an oil cup 2| or the like. The gland I1 closes the outer periphery of the chamber and is partly exposed to the oil so that the contacting surface of the gland and the band I! are maintained lubricated'.

' The oil alsoenters between the sides of the gland I! similarly lubricating the contacting faces ofA the glandand the sleeve I.

The surrounding cages for the cup leathers each comprises an annular memberindicated generally at 22, which is of channel shape in.

cross-section and opens inwardly; oneprojecting flange or side 2l of this annular member being disposed betweenhe radial' ilange of the corresponding cup leather and the adjacent parallel surface of the assembly, while the other or o pposite projeetingeflange or side of the member 22 extendsto a point adjacenLbut spaced from the-free-end portion of the other and longi- Atudinallyextending flange of the cup leather.

This arrangement thus provides an annular slot :ser limited width, which permits water te enter the cage and exert a force on the cup leather,

.but preventsr any foreign'matter of substantial size from entering the cage and then being driven 25 againsL the cup leather with probable damage thereto. The sealing means hereinfdescribed is especially designed for pumps on suction dredges, and through which pumpsmuch mud and debris, etc.passes. It is therefore necessary that the cup leathers be protected in the manner above described.

From the foregoing' description it wiu be readily seen that I have produced such a device as sub-v Letters Patent is:

1. A sealing gland for a pump including a housing, a rotary impeller in the housing and analined corresponding portion spaced from and parallel to said annularportion ofthe impeller, an ann cage of channel shape in cross section mounted on one of said portions and open in the directionf of the other portion, and an annular cup leather of right angle form^disposed in the cage with one flange ofthe leather engaging said other portion in sealing relation. and the other ilangeof the leather engaging the inner face ofA one side of the cage in sealing relation.l e

2. A device as in claim 1. in which the other side of the cage terminates in spacedrelation to but adjacent the free end portion of said one flange of the cup leather. e

` ROBERT GILMORE LE TOURNEAU.

having an annular portion, the housing including 1 

